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36 Cards in this Set
- Front
- Back
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normal microbial Flora
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- m/o that inhabit the skin and mucous membranes of healthy people
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Classification of normal flora
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1. Resident or constant (obligatory) - fixed types in a given area at a given age
2. Transient Flora (facultative) - non pathogenic or potentially pathogenic m/o that inhabit the skin or mucous membrane for hours, days, weeks (oral Flora, Flora of oesophagus or stomach |
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Exposure of an Individual to a m/o can lead to
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1. transiently colonize the Person
2. permanently -> 1+2 carriers without infection 3. produce a disease -> m/o that colonize humans do not disrupt normal body functions - disease occurs when the interaction btw. m/o and human lead to pathologic process characterized by damage of human host - fight against human resistance - and immune systeme |
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Causative agents
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1. Strict pathogens - no carrier/opportunists - not in normal Flora
e.g. M. tuberculosis N. gonorrhoeae Fr. tularensis Plasmodium spp. - Malaria Rhabdovirus - rhabies(Tollwut) 2. Opportunistic pathogens - typically members of the microflora e.g. S.aureus - ca 50% carrier E.coli - gasrrointestinal flora C.albicans - Candida/yeast - candiosis - opportunist establish disease when they get into unprotected sites by wounds (blood stream, tissue) |
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Risk factors of opportunistic infections
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1. Immunodeficiency - HIV
2. Chronic disease -Diabetes 3. Gastric ulcer 4. Stress 5. Antibacterial treatment - destroy also the usual microflora 6. Malnutrition 7. Avitaminosis etc. |
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Carrier state
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M/o -> host -> carrier state =source of infection without clinical symptoms
1. acute carriers (1 week - 1 month ->can release the m/o) 2. chronic carriers (month, years, permanently)/ e.g. S.aureus (20-40%) St. pneumoniae (40-70%) S. typhi |
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when does microflora appear?
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1. foetus is steril
2. during birth - 4-12h viridians Streptococci - 24-48h microflora in intestinal tract (Lactobacillus, Bifidobacterium spp., coliform bacteria) -breast fed children: m/o produce acid from carbohytrates and tolerate pH 5 - bottle fed: more mixed flora - lactobacilli are less prominant -Diet influences the relative composition of intestinalen and faecal Flora |
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skin
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Staphylococcus epidermidis 90%
Corynebacterium Propionibacterium - sebaceous glands -forehead and arm pit make pH 5,5 -Transitore microflora (can change) -resident (constant) microflora -10^3-10^4 /cm^2 |
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Conjunctiva
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Staphylococcus epidermidis 90%
Corynebacterium Propionibacterium - sebaceous glands -forehead and arm pit make pH 5,5 |
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Nasopharynx |
Staphylococcus epidermidis Corynebacterium Propionibacterium
Pathogens: Staphylococcus aureus Streptococcus pneumoniae Haemophilus influenza Neisseria meningidis |
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Oropharynx |
Staphylococcus Streptococcus Corynebacterium Propionibacterium
Anaerobes: Bacteriodes Fusobacterium Enterococcus
Pathogens: Streptococcus (alpha-hemolytic) Corynebacterium diptheria Klebsiella pneumoniae Pseudomonas aeruginosa |
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Oral cavity
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1.Viridans Streptococcus:
- Streptococcus salvarius - Streptococcus sanguis - Streptococcus milleri - Streptococcus mutans 2. Staphylococcus - Gr+ 3. Enterococcus - Gr+ 4. Veilonella - Gr- 5. Neisseria -Gr- 6. Bacteroides orale 7. Fusobacterium nucleatum 8. Actinomyces 9. Vibria 10. Spirillum 11. Spirocheta: -Treptonema orale - Borrelia buccalis - Leptospira dentium 12. Candida albicans - Saccharomyces 13. Prevotella melaninogenica 14. Porphyromonas gingivalis etc. |
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Oesophagus
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1.Viridans Streptococcus:
- Streptococcus salvarius - Streptococcus sanguis - Streptococcus milleri - Streptococcus mutans 2. Staphylococcus - Gr+ 3. Enterococcus - Gr+ 4. Veilonella - Gr- 5. Neisseria -Gr- 6. Bacteroides orale 7. Fusobacterium nucleatum 8. Actinomyces 9. Vibria 10. Spirillum 11. Spirocheta: -Treptonema orale - Borrelia buccalis - Leptospira dentium 12. Candida albicans - Saccharomyces 13. Prevotella melaninogenica 14. Porphyromonas gingivalis etc. |
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Stomach
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Sarcina ventriculi
Candida E. coli Helicobacter pylori |
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Small intestine |
1. upper part Streptococcus Staphylococcus Lactobacillus
2. distal part Bacteriodes Bifidobacterium Enterococcus Coliformbacteria |
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Large intestine |
Bifidobacterium Lactobacillus Enterococcus Bacteroides Bacillus Clostridium
Enterobacteriaceae: E.coliKlebsiellaProteus Coliform bacteria
Streptococcus faecalis Streptococcus lactis Fungi Veilonella Actinmyces |
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Kidney , Ureter , Urinary bladder
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steril
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Uretra
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Staphylococcus epidermidis
Streptococcus Corynebacterium spp. |
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vagina
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Staphylococcus epidermidis
peptostreptococcus Neisseria spp. Lactobacillus acidophilus Lactobacillus fermentans -> determine pH 3.5-4.7 against pusforming microflora Bacteroides Ureaplasma Mycoplasma |
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Dental caries
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- polyaethiologic diesease -> several reasons diet,time,teeth(genes),m/o
- beginning at the surface and going inward - surface enam is demineralized caused by acid products of bacterial fermentation - Dekomposition oft Dentin und cement Viridans Streptococcus: Str. mutans Str. sanguis Str. mitis -> carbohydrate polymers -> Actinomyces (anaerobes) -> Lactobacillus -> formation oft large amount of acid (ph < 5) -> high concentration of acid demineralize enamel and initiate caries |
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Positive aspects of Microflora |
1. absorption of nutrients and breakdown of products 2. synthesis of Vitamin K, B12 3. conversion of bile pigments and bile acids 4. antagonism to microbial pathogens 5. Stimulation of immune system |
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negativ aspects of microflora
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1. unprotected sites
Str. viridans - endocarditis bacteroides - bacteriemia, Peritonitis 2. Immunodeficiency patients AIDS 3. Disbacteriosis - disbiosis - qualitative alterations in the Flora or large inrease or decrease in total microbial population |
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role of microflora
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- source of carcinogenic factors
- Nutrients are chemically transformed as a result of bacterial metabolism in the intestinal tract - Many potential carcinogens become active after modification in the intestines - Usually modification is caused by intestine bacteria ferments: E.g. artificial sweeteners (cyclohexylamine sulphate) bacterial sulphatases are converted as active carcinogens cyclohexylamine of the urinary bladder - Experience based studies show that intestinal microflora is important in the pathogenesis of certain tumours |
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Soil microflora
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- The soil is one of the main reservoirs of microbial life
- Typical garden soil has millions of bacteria in each gram - The population is highest in the top few cm of the soil (3-8 cm) and decline rapidly with depth. |
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Soil
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1.Saprophytes
- in carbon cycle - in nitrogen cycle - ammonification - decay (Zerfall) organisms (aerobic and anaerobic bacteria, fungi) - nitrification -> Nitrosomonas, Nitrobacter -denitrification Pseudomonas, Bacillus spp. - Nitrogen fixation other biogeochemical cycles. 2.Pathogens and potentially pathogenic: -Endospores forming bacteria: Bac.anthracis - anthrax in animals - humans Cl.tetani - tetanus Cl.botulinum - botulism Cl.perfringens - gas gangrene - Enterobacteriaceae: Salmonella can survive for a few weeks or months Pseudomonas Staphylococcus M.tuberculosis |
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Aquatic microbiology - Content
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1.Saprophytes contamination from air, soil, plants
2.Pathogens and potentially pathogenic |
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water
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Water the source of enteric diseases fecal-oral route of transmission. Enterobacteriaceae
S.typhi - typhoid fever E.coli Shigella Vibrio cholerae Leptospira spp. Viruses HAV, POLIO |
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Air
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Microorganisms in the air M/o do not multiply in the air!
1.Saprophytes from soil, dust Sarcina Bac.subtilis Actinomyces Fungi 2.Potentially pathogenic and pathogens contaminated by carriers, objects the causative agents of respiratory tract infections |
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Bacterial infection
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Multiplication of an infectious agent within the body
Infectious disease: development of signs and symptoms of disease. Infectious disease = amount of m/o X the virulence of m/o // The host resistance and immune system |
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sources of exogenic infections
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1.Primary:
- Sick humans or carrier (a person or animal with asymptomatic infection that can be transmitted to another susceptible person or animal) - Sick animal or carrier -Insects 2.Secondary: environmental objects (water, air, food, soil). |
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pathways of transmission
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1.By contact: direct contact STD, fungal infections; indirect contact via secondary sources of infection. Human environment human (respiratory, enteric, wound etc. infections)
2.Vector-born infections: inoculation (malaria); contamination (ricketsioses); blood-born infections (HIV, HBV, HCV): instruments; blood preparations; tissues 3.Horizontal transmission (human - human) 4.Vertical transmission (mother - newborn). |
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Portals of entry
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1.Skin
2.Mucous membranes (respiratory, gastrointestinal, genital etc.) 3.Abnormal areas of skin cuts, burns, injuries |
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spreading of m/o in the organism
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1.Remain in the portals of entry - Local infections - Toxinemic infections
2.Spread in the organism: bacteremia - allows bacteria to spread widely in the body and permits to reach tissues; sepsis - bacteria multiply in bloodstream. |
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spreading of m/o in environment |
1.Sporadic infections occurring occasionally (Mumps) 2.Epidemic - a widespread occurrence of a disease in a community at a particular time (influenza) 3.Pandemic - prevalent over an entire country or the world (Cholera, HIV) 4.Endemic - found in a certain region (malaria) |
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The cycles of infectious disease |
1.Incubation period - no clinical symptoms (chickenpox, Mumps 21 days) 2.Prodrome - the period of unspecific, atypical symptoms (headache, vomiting) 3.Acme - the period of specific clinical symptoms 4.Recovery vor letalis |
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The characteristics of infectious disease
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1)The causative agent, the source of infection
2)The periods of infectious disease 3)Transmission 4)Immune response |
